The invention relates to an electrical control apparatus for the output of textile pattern data to groups of mechanical actuation elements that actuate needles for guiding thread in a textile machine.
A warp knitting machine with at least one laying bar and a control apparatus is known from the document DE 44 42 555 C2. The control apparatus therein has a main computer to which subordinate computers are attached in star formation via a serial bus. A subordinate computer is assigned to each member of a set of flexible converters disposed on the laying bar to drive that flexible converter. A serial-parallel converter is furthermore assigned to each flexible converter for addressing and data transmission. Each subordinate computer prepares data so that the flexible converter attached thereto is addressed individually and is subsequently provided with the control data.
It is disadvantageous to require a subordinate computer for each laying bar because of the high processing speed that is necessary. However, in the case of a large number of laying bars, as in the case of large textile machines, a correspondingly high number of subordinate computers is disadvantageously needed. The sequential addressing of the individual flexible converters requires the subordinate computers and electronic components to have a high processing speed because the flexible converters must be controlled rapidly and synchronously. Thus, an expansion of the number of laying bars also disadvantageously requires additional high-speed subordinate computers.
A control apparatus for piezoelectric actuators for a knitting machine is known from the document JP 82 18 255. The piezoelectric actuators each have a driver circuit which is connected to a control unit via a parallel bus. In this case the control unit selects a definite driver circuit of a piezoelectric actuator in a first step by the output of a parallel address signal and then transmits the pattern data to it in a second step.
It is disadvantageous that each piezoelectric actuator must first be activated for addressed data transmission via an additional address signal before it can receive the actual pattern information. Due to the relatively long data transmission times a controller of this type is not applicable without high technological expenditure for rapidly running textile machines or larger textile machines that require a large number of piezoelectric actuators.
An electronically controlled Jacquard machine, for controlling the warp thread of a weaving loom, is known from the document DE-OS 2 330 420. Therein, a serial-parallel converter is formed as a shift register, and is connected between an information transmitter and the flexible vibrators. It is disadvantageous that the shift register for each of the flexible vibrators has a register unit and all the flexible vibrators are driven simultaneously by the information transmitter per transmission cycle. Because of the foregoing, the number of transmissions per unit time, and thus the maximal operating speed of the Jacquard machine, is limited.